OSLO — A Norwegian expert reviewing the case of mass murderer Anders Behring Breivik, who thought he may have been wiretapped, turned out to be the source of a damaging leak in the case, he told a court hearing on Tuesday.

Tarjei Rygnestad, who heads a medical commission reviewing Breivik’s mental health report, filed a police complaint after public broadcaster NRK quoted verbatim from the commission’s discussion, only to be told that it was his phone which took a 53 minute call from NRK during the marathon session.

“We thought we may have been overheard or wire tapped,” Rygnestad said in court. “It turned out I had a 53 minute 30 second incoming call … from the switchboard at NRK,” he said.

NRK confirmed it overheard the conversation, saying a reporter called Rygnestad and then overheard the discussion after the expert accepted the call.

“One of our reporters called Rygnestad that day. The reporter understood that Rygnestad answered but waited to respond. As a result the reporter overheard what we perceived as a very interesting discussion,” NRK news editor Stein Bjoentegaard said.

The NRK report, which indicated there was serious disagreement within the commission, cast doubt on the panel’s approval of the report which declared Breivik psychotic, and may have contributed to the court asking for a second evaluation.

The second report drew opposing conclusions, saying Breivik, who killed 77 people last July, was sane, leaving the five judges to decide whether to send Breivik to a mental hospital or prison.

He said the overheard part of the discussion created a mistaken impression that there had been disagreement on the panel.

“From a small part of the meeting (NRK) drew the conclusion that there was disagreement, but there was no disagreement,” Rygnestad said.